Tool operating mechanism



Dec 20, 1949 E. H. sHAFF TOOL OPERATING MECHANISM 2 Sheets-Sheet 1 Filed March 29, 1945 Dec. 20, 1949 E. H. SHA1-F 2,491,624

TOOL OPERATING MECHANISM Filed March 29, 1945 2 Sheets-Sheet 2 j?? Ve?? fr" ff/areys Patented Dec. 20, 1949 2,491,624- y Toor. OPERATING MECHANISM Ernest H. Shaff, Spring Lake, Mich., assignor to Keller Tool Company, Grand Haven, Mich., a

corporation of Michigan Application March 29', 1945, Serial No. 585,470 s claims. (Cl. "J4- 60) This invention relates to tools involving a power operated reciprocating element.

Among .other objects, the invention aims to provide an improved and simplified wobble mechanism for producing a short-stroke reciprocating movement in such tools.

Other objects and advantages will become apparent from the following description of illustrative tools embodying the invention and shown in the accompanying drawings.

In said drawings:

Figure 1 is a longitudinal section of a ratchet wrench embodying the inventive mechanism;

Fig. 2 is an elevation of the tool taken from a plane at right angles to that of Fig. 1;

Fig. 3 is a front end view of the tool;

Fig. 4 is an elevation of the drive shaft of the` tool:

Fig. 5 is an elevation of the outer race for the ball bearing;

Fig. 6 is a section of such race taken on the plane 6--8 of Fig. 5;

Fig. '7 is a longitudinal view partly in section of a filing tool embodying the invention; and

Fig. 8 is a sectional front end view of the tool which power is delivered by a rotating shaft substantially coaxial with the handle of the tool. To convert this rotary movement, which is inherently high speed, into an axial reciprocating movement imposes a severe task on the converting mechanism.

In the illustrative hand tools, the converting mechanism is in the form of a wobble or swash plate which, although designed to convert rotary movemrnt into a short-stroke reciprocating movement operating substantially in line with or in the same general direction as the axis of rotation, has not heretofore been well adapted for use in tools of this character. In the ratchet wrench illustrated in Fig. 1, the power unit I0, advantageously either an air or an electric motor, drives shaft II and is located in the housing I2 which may constitute the handle or a continuation of the handle of the tool. In the present case, the housing I2 is located Ibeyond the handle proper and is of slightly larger diameter than. the handle I3. The latter is provided with a controlling element Il for controlling the motor. Any appropriate means may be employed for rotating the driving shaft.

As here shown, the drive shaft operates in ball bearings I5 and I6 and carries at its outer end a spindle I1 provided with an inner race portion IB for a ball bearing located in a plane at an angle to the axis of the shaft. Such inner race portion may advantageously be integral with, i. e.,

formed directly in, the spindle I1. The outer bearing race I9 is formed in an annular ring which also constitutes the wobble plate itself. It is provided with connecting means in the form, of a projection 2Il having a spherical surface 2l by means of which the reciprocating component of the movement of the wobble plate is transmitted to the driven element, in this case, a pawl or push rod 22 for operating the ratchet socket 23 of the wrench. It will be understood that the connection with the push rod holds the wobble plate against rotation with the spindle and limits the movement of its projection 20 to reciprocation.

The contour of the bearing surface for the outer race is of such depth, i. e., substantially semicircular in section, as to be capable oi assuming and transmitting radial and axial forces or thrusts in both directions. the bearing are advantageously assembled in the bearingr without the usual cage or lling slot by temporarily causing the balls to adhere in proper place in the outer race while the latter is slipped over the spindle I1 and the balls are seated against the inner race portion I8. This may be easily effected by using a sufliciently heavy grease on the balls to hold them thus during assembly. The balls are held in their assembled position and the bearing clearances adjusted by a removable and adjustable inner race element 26 threaded on a stud 25 of reduced diameter integral with the spindle. A lock nut 21 holds the element 26 in adjusted position. The race element 26 and the inner race portion IB constitute together an inner race of such depth as to Abe capable of assuming and transmitting radial and axial thrusts in both directions. Ability to adjust the inner race element I8 makes it possible to obtain adequate but limited running clearances (and in addition to take up wear) in the bearing without the exceedingly accurate machinery which would otherwise be necessary for bearings having races of such depth.

It is evident from the foregoing that the formation of the inner race directly on the driving spindle and the outer race directly in the wobble plate itself not only provides a direct driving connection of few parts but a simplied ball bearing capable of eiciently transmitting radial and axial forces in both directions. Assembly of the bearing as aforesaid makes it unnecessary to employ either a bearing cage or a bearing filling slot in the race.

The reciprocating push rod 22 is connected to the wobble plate in the present instance simply by providing it with a socket 28 in which the connecting projection 20 seats. This connection and the lower portion of the rod arecovered by a removable plate 29 which prevents displacement of the rod and presses it toward the ratchet.

The balls 24 of It is, however, sufilciently flexible to allow oscillation of the rod against the ratchet teeth. `The rod reciprocates between and is guided by side plates which project beyond the body of the tool and between which the socket operating ratchet 23 rotates. The latter is provided with a socket 3| of non-circular section for receiving various wrench elements and opposite annular bearing flanges 32 which are seated in corresponding circular bearing openings 33 in the side plates. The latter are connected, by bolting in this case, to the opposite sides of a web 34 projecting from, and in this case integral with, the housing 35 surrounding the wobble plate. A pawl 36 seated in a recess in web 34 and pressed by spring 31 against the ratchet serves to prevent reverse rotation thereof on return movement of rod 22.

In Figs. 7 and 8 is illustrated the application of the inventive principle to a diiereni; tool, in this case, a tool for iiling or the like in which a iile, saw or other device is reciprocated axially of the body of the tool. In the illustrative tool, the drive shaft spindle 40 is rotated by a power unit carried inside the handle 4I and housing 42 of the tool, but it should be understood that here also other and separate means may be used for rotating spindle 40. The controlling element 43 for the present power unit is operated simply by grasping the handle of the tool.

The inner bearing race portion 44 is formed integral with the extremity of the spindle 42 and lies in a plane at an angle to the axis of rotation of the spindle. The outer race 45 is also formed directly on the wobble plate 46 substantially as previously described. Also similarly the wobble plate is provided with a projection 41 having a spherical surface 48 for operating the reciprocating element. The latter is here shown in the form of a socket 4 9 to which the metal cutting tool, such as a file, is adapted to be connected, in this case by clamping the same in the socket by a set screw 50 or the like. The socket reciprocates within a central bore in housing 5I and is provided with an offset portion 52 carrying a socket 53 in which the driving projection 41 is seated. The socket or some portion of its exterior and the guiding bore 5I is preferably noncircular in section to prevent rotation or twisting of the tool as it reciprocates. The balls ofthe bearing and the outer race are assembled and positioned as previously described and held in operating condition by an inner race element 54, in this case in the form of a screw 55 which is threaded into a recess 56 in the spindle coaxial with the inner race 44.

The screw is provided with a driving slot or the like 51 by means of which the inner race may be adjusted for smooth operation and to take up wear. It is locked in adjusted position by a separate socket set screw 58. As in the other y bination comprising a rotary driving spindle having an inner ball bearing race portion formed therein in a plane at an angle to the axis of spindle rotation. said spindle having a threaded stud coaxial with said race portion, a wobble plate having an outer ball race therein of sufilcient depth to assume axial thrusts in both directions, a removable inner race element threaded to said spindle stud and adjustable relative to said inner race portion and forming with the latter an inner race of suflicient depth to transmit axial thrusts in both directions, a threaded locking element for locking said inner race element in adjusted position, and a reciprocable tool element operatively connected with said wobble plate.

2. In a tool of the character described, the combination oi a rotary driving spindle having an inner ball bearing race portion formed thereon in a plane at an angle to the axis of spindle rotation, said spindle having a threaded recess coaxial with said race portion, a wobble plate having an outer ball bearing race therein of sufilcient depth to assume axial thrusts in both directions, a removable inner ball bearing race element threaded into said recess and adjustable relative to said rst inner race portion and coacting with the latter to form an inner race of sufilcient depth to transmit axial thrusts in both directions, a threaded locking element for-locking said inner race element in adjusted position, and a reciprocable tool element operatively connected with said wobble plate.

3. In a tool of the character in which rotational motion is changed to reciprocating motion, a rotary driven spindle having an inner ball bearing race portion formed thereon at an angle to the axis of the spindle, a removable ball bearing race portion adapted to coact with said iirst portion to form an inner ball bearing race, a wobble plate having an outer ball bearing race formed thereon, said outer race being concentric with and adapted to overlie each of said inner race portions, a locking element having a screw threaded engagement with the spindle in coaxial relation with `the ball bearing race and bearing on said removable race portion to hold the latter in adjustable position with respect to the spindle race portion, and a reciprocable tool y element operatively connected with said wobble plate.

ERNEST H. SHAFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 577,103 Denison Feb. 16, 1897 756,700 Poirier Apr. 5, 1904 829,658 Leavitt Aug. 28, 1906 .1,679,884 Thomas Aug. 7, 1928 `1,901,981 Ousback Mar. 21, 1933 1,973,064 Gwinn, Jr Sept. 11, 1934 2,161,210 Woolkes June 6, 1939 FOREIGN PATENTS Number Country Date 555.592 Germany Jan. 28, 1933 

